Method for connecting tubular members

ABSTRACT

A method is provided for joining together two lengths of pipe in an environment wherein conventional methods are not suitable, e.g., underwater. The method includes introduction of fluid under pressure from a remote source into a coupling member surrounding a pipe length to be joined, the fluid under pressure acting to effect the coupling to grip the pipe length and then become sealingly engaged therewith. In one embodiment, a method is provided wherein a hardenable material is used which is in the fluid state when introduced into the coupling, but which upon setting hardens into the solid state to form a relatively permanent connection.

United States Patent 1191 Arnold, James F.

[54] METHOD FOR CONNECTING TUBULAR MEMBERS 1 Jan. 30, 1973 2,748,8696/1956 Hager ..285/96 3,097,866 6/1963 Dversen ..'....285/18 3,142,5007/1964 Wesse1er.... ..285/96 3,278,193 10/1966 Groner et al. ..29/446 X2,922,664 1/1960 Risley et a1 ..285/96 2,226,304 12/1940 Dillon..285/111 X [22] Filed: April 30, 1970 Primary Examiner-Charlie T. Moon[21] App! 33494 Att0rney-Arnold, White & Durkee, Frank S. Vaden,

Re'ated Application Data 111, LOUIS T. Plrkey and John F. Lynch [63]Continuation of Ser. No. 709,678, March 1, 1968, 57 ABSTRACT abandoned,which is a continuation-in-part of Ser. No. 486,154, Sept. 9, 1965, Pat.No. 3,393,926. A method is provided for joining together two lengths ofpipe in an environment wherein conventional [52] U.S. Cl. ..29/460,285/18, 285/96, methods are not suitable, e.g., underwater. The 285/101method includes introduction of fluid under pressure [51] Int. Cl ..B23p3/00, 1323p 19/04 from a remote source into a coupling member guy. Fieldof Search rounding a pipe length to be joined, the fluid under illpressure acting to effect the coupling to grip the pipe length and thenbecome sealingly engaged therewith. References Cited In one embodiment,a method is provided wherein a v UNITED STATES PATENTS hardenablematerial is used which 15 m the fluid state when introduced into thecoupling, but which upon 2,001,946 5/1935 Tschappat ..285/148 settinghardens into the solid state to form a relatively Penick et al... Xpermanent connectior 2,350,867 6/1944 Bean et a1 ..285/96 2,536,8981/1951 Works ..285/96 2 Claims, 7 Drawing Figures 2,582,518 1/1952 Works..285/96 ./"Z3fl Pmtmmm 30 I975 SHEET 2 BF 3 ATTO/P/VE VJ METHOD FORCONNECTING TUBULAR MEMBERS REFERENCE TO RELATED APPLICATIONS This is acontinuation of my copending application Ser. No. 709,678, filed Mar. 1,1968, now abandoned, which is a continuation-in-part of my applicationSer. No. 486,154, filed Sept. 9, 1965, now US. Pat. No. 3,393,926.

BACKGROUND AND SUMMARY OF THE INVENTION This invention relates to amethod for joining a length of pipe to another length of pipe or othertubular member, and for repairing a faulty section of pipe. Thisinvention is especially useful in those environments in whichconventional methods are not suitable, and requires no specialpreparation or pretreatment of the lengths of pipe to be joined.

Briefly, the invention comprises a method suitable for joining togetherlengths of pipe comprising affixing a coupling to the lengths of pipe tobe joined, and introducing into said coupling a fluid under pressure inorder to securely grip each of said lengths of pipe, whereby there isformed within said coupling an area in fluid communication with saidlengths of pipe, and in fluid isolation with all areas exterior of saidcoupling.

Many problems are inherent in connecting together two or more conduitsin certain working environments, for instance underwater or in areaswhere there exists the danger of explosion. With the rapid increase inthe use of pipes and other conduits in these areas within recent years,this problem has become one of major concern among workmen andengineers.

This invention provides methods for solving this problem, and forensuring the safe and easy joining of conduits in such problem areaswithout the necessity of costly or laborious pretreatment.

BRIEF DESCRIPTION OF THE DRAWINGS In order that the manner in which theforegoing and other objects attained in accordance with this inventioncan be understood in detail, advantageous embodiments of the inventionwill be described with reference to the accompanying drawings, whichform a part of this specification, and wherein:

FIG. 1 is an elevational view, partly in section, of a coupling usefulin the methods of this invention, showing the coupling in positionaccording to one embodiment of the invention, after two lengths of pipeto be joined have been inserted in the coupling, but before the couplingis actuated.

FIG. 2 is a view similar to FIG. 1, illustrating the coupling of FIG. 1in its actuated position.

FIG. 3 is an elevational view, partly in section, of another form ofcoupling useful with the methods of this invention.

FIG. 4 is a perspective view of a means for connecting conduits inaccordance with another embodiment of this invention.

FIG. 5 is perspective view of a means for connecting conduits inaccordance with yet another embodiment of this invention.

FIG. 6 is an elevational view, partly in section, of a means foradapting a well-head, in accordance with yet another embodiment of thisinvention.

FIG. 7 is a pictorial view illustrating a particularly preferredarrangement for introducing a pressurized fluid into another form ofcoupling useful in connection with this invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Referring now to thedrawings in more detail, there is illustrated in FIGS. 1 and 2 acoupling 1 useful with the method of one advantageous embodiment of thisinvention. Coupling 1 includes an elongated tubular housing or casing 2having ends 3 and 4, a cylindrical exterior surface 5, a generallysmooth cylindrical internal surface 6, and an opening 7 therein near thetransverse center thereof. The coupling 1 is thus seen to be in the formof a sleeve having a diameter which is suitable for fitting entirelyaround the lengths of pipe or other tubular members to be joined. It isnot necessary for the diameter of the coupling to be constant, as seenin FIG. 5, and the coupling may be constructed of two sleeves meeting asin the form of the T-section of FIG. 4. Still, the couplings of theinvention in all embodiments are generally tubular in configuration andtherefore may be referred to herein as sleeves.

Means for securely engaging the two lengths of pipe 9 and 10 to bejoined and for forming a permanent seal with these lengths of pipe arelocated inside the casing 2 and occupy an annular area the insidediameter of which is slightly greater than the outside diameter of thetwo lengths 9 and 10.

The above-mentioned means for engaging the pipe and forming a permanentseal have been desirably found to include (I) means for guiding thelengths of pipe into the coupling; (2) means for securely gripping thelengths of pipe; (3) means for effecting sealing engagement with thepipe lengths; and, (4) means for actuating said gripping and sealingmeans.

Guide means which are desirably provided on the coupling 1 forfacilitating insertion of pipe lengths, conveniently take the form ofmembers 11 and 12 located at each end of the coupling. In the FIG. 1embodiment, such guide members are constructed as separate parts firmlysecured to the ends 3 and 4 of casing 2 as by welds l3 and 14. It isunderstood, however, that guide members 11 and 12 could be constructedas integral parts of the casing 2, if desired. Guide members 11 and 12of this embodiment include a conical-shaped inwardly tapering surface ina direction away from the transverse center of the coupling whichprovides a cam surface 15, and a conical-shaped outwardly taperingsurface in a direction away from the transverse center of the couplingwhich provides a guide surface 16. Cam surface 15 serves to convert aportion of the longitudinal movement of the gripping means into radialmovement when such means contact this surface, thus allowing thegripping means to firmly grip the lengths of pipe to be joined. Guidesurface 16 serves to guide the lengths of pipe to be joined into thecoupling. While it would not be absolutely necessary to provide both camsurface 15 and guide surface 16 in a single part, such an arrangementhas been found to be particularly advantageous.

Gripping means are conveniently located axially inwardly of said guidemeans, and may desirably take the form of slips, segments of which areshown at 17 and 18. Such slips are movable axially within a certaindistance inside the members 11 and 12 which serve as slip bowls. Anyconvenient number of slip segments may be included in each slip bowl,for example three. Such segments are desirably constructed of steel, andinclude at the inside diameter thereof radially inwardly facing teeth 19and radially outwardly facing tapered surfaces 20, conical-shapedtapered surface 21 at the outer diameter thereof and generally flat endfaces 22. The tapered surfaces 21* are adapted to contact the similarlyshaped cam surfaces of guide members 11 and 12 whereupon said slips arecaused to move radially inwardly. As is readily seen from FIGS. 1 and 2,the

slips are free for axial movement within the area 23, and 23a denotesthe unoccupied area after the slips have been so moved by a longitudinalforce transmitted by junk ring 25, which in this embodiment abuts theend faces 22 of slip segments 17. Junk rings 25 and 26 are desirablyconstructed, for example, of hard steel, and transmit axial force fromengaging and sealing means, such as the side face of end packing ring27, to the slips.

Means for securely engaging the pipe lengths to be joined and forming aseal therewith are conveniently located between the slips and thetransverse center of the coupling, and conveniently take the form ofpacking rings 27, 28. Packing rings 27 and 28, which are no thicker thanthe interior dimensions of the coupling, must be resilient to someextent so that when placed under pressure they will deform to firmlypress against the lengths of pipe 9 and 10 to be joined, as is clearlyshown in FIG. 2. Any suitable material of construction may be used forrings 27, 28 as long as it is resilient and generally heat resistant.Hard rubber,

asbestos, lead, and soft copper have been found to be useful. Althoughthree packing rings 27, 28 are illustrated in FIGS. 1 and 2 at each endof the coupling, it is understood that any suitable number might beemployed. Also, the packing rings may be of any suitable shape, forexample V-shaped rings.

As a further sealing means against the length of pipe to be joined, ithas been found advantageous to include in some embodiments a hard rubberinsert 30 adjacent the slips on the side thereof away from thetransverse center of the coupling. Under pressure, this insert will alsobe deformed to occupy the annular space between the guide and slip bowl1 l, and the pipe 9, to thus form an effective seal therebetween.

Power operated means for actuating the engagement means and the grippingmeans may take various forms, but the embodiments shown in FIGS. 1-3have been found particularly advantageous. Such means are illustrated inFIGS. 1 and 2 as a pair of members movable axially along the couplingapart from one another upon the application of pressure therebetween.Thus, such members may take the form of male piston 31 and female piston32. Male piston 31 is desirably constructed as shown in FIGS. 1-3,wherein it is a generally tubular member having an elongate portionwhich includes a cylindrical external surface 46 and a cylindricalinternal surface 47, and also having an enlarged end portion 42. Endportion 42 includes a generally flat annular end face 43, an oppositeannular face 48, and an outer cylindrical surface 44 which has adiameter substantially equal to the diameter of the inner wall 6 ofcasing 2, and which is sealingly engaged with the inner surface 6 of thecasing 2 between annular faces 43 and 48. At the end of the male piston31 opposite the generally flat annular face 43 is another generally flatannular end face 45. Female member 32 is desirably constructed as shownin FIGS. 1 and 2, wherein it is a generally tubular member which has anouter cylindrical surface of a diameter substantially equal to thediameter of the inner wall 6- of easing 2. It is mounted with the outercylindrical surface in sealing engagement with the inner wall 6. Aninner cylindrical surface is in sealing engagement with surface 46 ofthe elongate portion of male piston 31. In this embodiment, the piston32 includes a radially inwardly projecting flange 49 at one end thereof,and a generally flat annular end face 50 at the opposite end thereof.Male piston 31 and female piston 32 are separated in the initialposition by a space 33 which is in communication through inlet 34 inopening 7 with an inlet conduit 35. Space 33 is defined by annular face48 and cylindrical surface 46 of male piston 31, end face 50 of femalepiston 32, and the inner wall 6 of casing 2. As is readily apparent fromFIGS. 1 and 2, pistons 31 and 32will, upon application of pressure (asby filling the area 33 between the pistons with a fluid under pressure),slide apart until the slips are no longer free to move. At this point,the pressurized fluid will occupy an increased area 33a as seen in FIG.2, and the packing rings 27, 28 will be in sealing engagement with thelengths of pipe 9 and 10, as seen at 36 in FIG. 2.

Means are employed to exert pressure against the pistons 31 and 32. Suchmeans conveniently take the form of a pressurized fluid, and it has beenfound particularly advantageous to introduce a hardenable material suchas cement or an epoxy resin into the area 33. Upon setting, thehardenable material will thus occupy the enlarged area 33a without thenecessity of further application of pressure in this area, and thus theconnections at the inlet 34 may be removed. In this manner, convenientmeans are employed to lock the power operated means so that space 33a isnot decreased.

Suitable sealing means such as o-rings 37, 38, 39 and 40 are employed toensure a tight seal as the male and female pistons move relative to eachother.

Checkvalve 41 is desirably included in the inlet conduit to admit fluidinto the space 33 while preventing the fluid in that area from returningto the inlet conduit 35.

In FIG. 3 is illustrated an embodiment which is especially useful whenonly only one free length of pipe 53 is to be joined to a manifold orthe like. In this embodiment, the cylinder 54 is fixed, and in thisembodiment there is no need for separate casing 55 in the area of thiscylinder, as it is desirably formed as an integral unit with the casing.At the end of the coupling adjacent pipe 53 are slips 56 resting inguide and slip bowl 57. Here again a resilient insert 58 is desirablyincluded. Between the inlet conduit 59 and slips 56, as in the FIG. 1embodiment, are junk ring 60, packing rings 61, and annular piston 62.At the end opposite pipe 53 there are no slips, packing rings, guide,etc., as such are unnecessary. As will be readily understood, thisembodiment operates in the same manner as the FIG. 1 embodiment, exceptthat upon pressurizingthrough inlet 59 only piston 62 and its associatedrings and slips are movable, while cylinder 54 is fixed.

The FIG. 3 embodiment is especially useful in the embodimentsillustrated in FIGS. 4 and 5. In the FIG. 4 embodiment, three lengths ofpipe 64, 65, and 66 are joined at a tee 67. In this instance, threeseparate couplings, (for instance those of the FIG. 3 type) 68, 69 and70, are securely fastened to tee 67 and are used to securely lock thepipe sections thereto.

In the FIG. 5 embodiment, a length of pipe '72 is joined to a length ofpipe 73 oflarge diameter by means of two couplings 74 and 75 constructedin accordance with this invention which are joined together by acoupling piece 76. If the couplings 74 and 75 are constructed inaccordance with the FIGS. 1-2 embodiment, rather than the FIG. 3embodiment, and the lengths of pipe 72 and 73 are inserted in thecoupling in a manner such that each pipe length is gripped by both setsof gripping means, an embodiment is provided which is especiallydesirable in those instances where one or more of the pipe lengths 72,73 may be in compression rather than tension.

As will be readily recognized, any number of different lengths of pipe,or any different sizes of pipe, or any type of connection can be readilyemployed in the manner generally illustrated by the FIGS. 4 and 5cmbodiments. For one example, a number of lines from separate offshorewells may be joined at a common manifold.

As one example of the operation of a coupling constructed in accordancewith the embodiment of FIGS. 1 and 2, it may be desired to join togethertwo lengths of pipe 2 and 3 which are underwater. Coupling 1 will belowered to a diver, who guides pipe 9 into the coupling by means of theguide surface 16 of member 11 and similarly pipe into the coupling bymeans of guide member 12. After the pipes 9 and 10 are in approximatelythe position shown in FIG. 1 (stops or any other convenient means may beemployed to signify to the operator when this position has been reached)all air and/or water may be bled out of the area 33 by means of arelease line (not shown) to at least partially evacuate the area 33.Then a pressurizing fluid such as a hardenable cement is brought intothe area 33. This causes longitudinal movement of the pistons 31 and 32,which forces, through packing rings 27, 28 and junk rings 25, 26 theslip segments 17, 18 against the cam surfaces of guide members 11, 12.The slips are moved radially inwardly in response to this axial movementuntil they firmly grip the outer surfaces of pipes 9, 10. After theslips are thus set, further movement of the pistons causes axialcompression of the packing rings 27, 28 which expands these ringsradially into sealing engagement with the outer surface of the pipes 9and 10. The inlet connection is then removed and the pipes 9 and 10 areseen to be securely joined, with the flow therebetween progressing, ofcourse, through the area 8 which is in fluid communication with theinterior of each of pipes 9 and 10 and in fluid isolation with all areasoutside coupling 1.

If the tool is to be used to repair a faulty section of pipe, it isusually preferred that the pipe length be cut in the area of the faultysection. Then the coupling is guided over the severed portion and set asdescribed above. It is possible that in some instances it will bedesired to slide the coupling for a long distance over a length of piperather than to cut the pipe in the damaged area.

In FIG. 7 is illustrated a particularly advantageous means forpressurizing a coupling 78 which is located adjacent the'floor 79 of theocean or other body of water 80. As illustrated, such means convenientlytake the form of a tubular member 81 which contains the material to beused for pressurizing the coupling, as for example a hardenable epoxyresin 82. The tube 81 is adapted to be readily connected through aflexible conduit 83 to a pump 84 in fluid communication with a source offluid under pressure at the surface of the water, for example on a boat85, and is further adapted to be readily connected through a conduit 86to the coupling 78. The tube 81 is comprised of a generally cylindricalhollow casing or housing 88 having caps 89 and 90 at the extremetiesthereof, and a piston 91 axially movable therein, said piston beingconveniently held in sealing engagement with the casing 88 as by meansof seal 92. There is provided means such as nozzle 93 at the end of thetube 81 adjacent cap 90 for exit of the material 82 into the conduit 86.

As will be readily understood, in a preferred embodiment of theoperation of this pressurizing device, a diver may take with him to thelocation of the coupling the tube 81, and at that point connect the tubeto the flexible conduit 83 and the conduit 86. The pressurized fluidfrom the source at the surface is then pumped into the member 81, movingthe piston downwardly in the tube and forcing the hardenable materialthrough nozzle 93 into the conduit 86 and thence into the coupling 78.Actually, conduit 86, which may be flexible, may not be necessary as thenozzle 93 may be connectable directly onto the coupling 78.

The hardenable material thus fills space 33 and forces pistons 31, 32apart. As will be understood to those skilled in the art, the hardenablematerial such as an epoxy may include a catalyst or setting agent tocause it to set or become hardened at a certain time.

In FIG. 6 is illustrated another particularly advantageous applicationof this invention. Here the coupling 95 is illustrated in its use as awell-head adapter. As will be readily understood from the abovedescription, a coupling 95 constructed, for example, in

a manner illustrated in the embodiment of FIG. 3, comprising housing 96,inlet 97 in communication with an annular space (not shown), pistons(not shown), engaging means (not shown), slips 98 and insert 99, isinserted onto the tubular casing 100 of a well, and is joined as by weld101 to a casinghead 102. A blowout preventor or well assembly having abottom flange 103 is securely joined as by bolts 104 to the casinghead,with seal rings 105 being inserted to prevent unwanted fluidcommunication between the interior of the casing and the area exteriorcasinghead 102.

It is seen from the above description that methods are provided forjoining together two lengths of pipe, requiring no special preparationof the ends of the pipe to be joined. The methods of the invention areespecially useful in joining lengths which are located in difficultworking environments. For example, the invention is especially suitablefor work underwater, as in connection with offshore wells. As anotherexample, the invention is particularly useful in hazardous environmentssuch as refineries where there is constant danger of explosion, andconventional method which employ welding are ruled out because of thisdanger.

Still further, the invention is especially advantageous for use inconnection with shipboard piping systems.

those skilled in the art that various changes might be made withoutdeparting from the scope of this invention. It will be understood thatthe term pipe as used in the appended claims would include a structuresuch as the casing illustrated in FIG. 6.

I claim: 1. A method suitable for connecting two pipe sections indifficult working environments, comprising:

providing an elongate sleeve having a diameter suitable for fittingaround said pipe sections, said sleeve having a first opening at one endthereof for receipt of one of said pipe sections, a second opening atthe opposite end thereof for receipt of the other of said pipe sections,and a third opening in a side wall of said sleeve and communicating witha single annular chamber in said housing; supporting in said sleevemeans axially spaced from said annular chamber to separately grip eachof said pipe sections and means to separately sealingly engage each ofsaid pipe sections, said gripping and sealing means being simultaneouslyresponsive to fluid pressure applied through said single annular chamberfor actuation thereof; subsequently guiding said pipe lengthsrespectively into said first and second openings in said sleeve;

providing a source of fluid under pressure, and conduit means fortransporting said fluid from said source to said third opening in saidsleeve;

attaching said conduit means to said third opening and to said fluidsource, to establish fluid communication therebetween;

introducing fluid from said fluid source through said conduit means intosaid third opening and thence into said annular chamber, said fluidserving to exert force in a direction axially away from said annularchamber, to

move each of said gripping means simultaneously into gripping engagementwith its respective pipe section, and

move said engaging means simultaneously into sealing engagement withsaid pipe sections, thereby sealing each of said sections to saidsleeve;

terminating fluid communication between said fluid source and saidsleeve; and,

securely retaining said fluid in said sleeve, to thereby form a firmconnection between said sections of pipe, and whereby fluidcommunication under high pressure may be established through said pipesections and said sleeve.

2. The method in accordance with claim 1, wherein said fluid introducedinto said sleeve is a hardenable material which, upon setting, hardensto form a permanent connection between said pipe sections and saidsleeve.

1. A method suitable for connecting two pipe sections in difficultworking environments, comprising: providing an elongate sleeve having adiameter suitable for fitting around said pipe sections, said sleevehaving a first opening at one end thereof for receipt of one of saidpipe sections, a second opening at the opposite end thereof for receiptof the other of said pipe sections, and a third opening in a side wallof said sleeve and communicating with a single annular chamber in saidhousing; supporting in said sleeve means axially spaced from saidannular chamber to separately grip each of said pipe sections and meansto separately sealingly engage each of said pipe sections, said grippingand sealing means being simultaneously responsive to fluid pressureapplied through said single annular chamber for actuation thereof;subsequently guiding said pipe lengths respectively into said first andsecond openings in said sleeve; providing a source of fluid underpressure, and conduit means for transporting said fluid from said sourceto said third opening in said sleeve; attaching said conduit means tosaid third opening and to said fluid source, to establish fluidcommunication therebetween; introducing fluid from said fluid sourcethrough said conduit means into said third opening and thence into saidannular chamber, said fluid serving to exert force in a directionaxially away from said annular chamber, to move each of said grippingmeans simultaneously into gripping engagement with its respective pipesection, and move said engaging means simultaneously into seaLingengagement with said pipe sections, thereby sealing each of saidsections to said sleeve; terminating fluid communication between saidfluid source and said sleeve; and, securely retaining said fluid in saidsleeve, to thereby form a firm connection between said sections of pipe,and whereby fluid communication under high pressure may be establishedthrough said pipe sections and said sleeve.
 1. A method suitable forconnecting two pipe sections in difficult working environments,comprising: providing an elongate sleeve having a diameter suitable forfitting around said pipe sections, said sleeve having a first opening atone end thereof for receipt of one of said pipe sections, a secondopening at the opposite end thereof for receipt of the other of saidpipe sections, and a third opening in a side wall of said sleeve andcommunicating with a single annular chamber in said housing; supportingin said sleeve means axially spaced from said annular chamber toseparately grip each of said pipe sections and means to separatelysealingly engage each of said pipe sections, said gripping and sealingmeans being simultaneously responsive to fluid pressure applied throughsaid single annular chamber for actuation thereof; subsequently guidingsaid pipe lengths respectively into said first and second openings insaid sleeve; providing a source of fluid under pressure, and conduitmeans for transporting said fluid from said source to said third openingin said sleeve; attaching said conduit means to said third opening andto said fluid source, to establish fluid communication therebetween;introducing fluid from said fluid source through said conduit means intosaid third opening and thence into said annular chamber, said fluidserving to exert force in a direction axially away from said annularchamber, to move each of said gripping means simultaneously intogripping engagement with its respective pipe section, and move saidengaging means simultaneously into seaLing engagement with said pipesections, thereby sealing each of said sections to said sleeve;terminating fluid communication between said fluid source and saidsleeve; and, securely retaining said fluid in said sleeve, to therebyform a firm connection between said sections of pipe, and whereby fluidcommunication under high pressure may be established through said pipesections and said sleeve.